How South Korea is governed: a one-term president and an assembly that can stop one

What the president can and cannot do

The president is head of state and head of the executive, elected by universal, equal, direct and secret ballot for one five-year term with no re-election (Articles 67 and 70). The office commands the armed forces, appoints the prime minister with the National Assembly's consent, and presides over the State Council of ministers. A candidate must be at least forty on election day. If the office falls vacant, a successor has to be elected within sixty days, which is why the two early elections of the Sixth Republic, in 2017 and 2025, came so quickly after the court rulings that caused them.

The powers that once let presidents rule without the assembly are now tied to it. Emergency financial orders under Article 76 lapse at once if the assembly does not approve them. A president may proclaim martial law under Article 77, but must notify the assembly without delay, and when a majority of all members asks for it to be lifted the president "shall comply". That clause was tested on the night of 3 December 2024, when troops were sent to stop the assembly convening and 190 legislators got into the chamber and voted to end the declaration at 1.00 am.

The prime minister is appointed rather than elected and, under Article 86, may not be a serving member of the military. The assembly can pass a recommendation for the removal of the prime minister or a minister with a majority of all its members.

How the National Assembly is elected

The legislature has one chamber, the National Assembly, of 300 members elected for four years. The constitution sets a floor of 200 members and leaves the rest to law. Most seats are won in single-member constituencies by whoever gets the most votes, and the rest are allocated nationally from party lists; at the election of 10 April 2024 the split was 254 constituency seats and 46 proportional ones, according to the IPU's record of the results.

That election is the one the present assembly was chosen at. The Center for Strategic and International Studies (CSIS) put turnout at 67%, the highest in 32 years, and the IPU recorded a record 60 women elected, up from 57 in 2020.

The large parties ran satellite lists for the proportional seats and absorbed them afterwards, which is why sources disagree on the Democratic Party's total: the IPU counts 161 seats for the party itself and 171 when the assembly convened on 30 May 2024, CSIS and Wikipedia count 175, and Freedom House 176.

The assembly's size decides what a majority can do. A majority of all members can demand an end to martial law. Three-fifths, 180 seats, ends a filibuster, and CSIS noted that the 2024 result fell short of it. Two-thirds, 200 seats, is needed to impeach a president or to pass a constitutional amendment, which then goes to a referendum.

Why presidents so often face a hostile assembly

The two calendars do not line up. A president serves five years and the assembly four, so assembly elections fall at different points in each presidency, and a president can win narrowly and then govern against an assembly the other side controls.

The presidency elected in 2022 is the plain case. Yoon Suk Yeol won that March by less than one percentage point, 0.7% in the Congressional Research Service count, and took office facing an assembly in which the opposition held about 60% of the seats. By January 2024, according to CSIS, 29.2% of the bills submitted to that assembly had been enacted, against 61.4% under the previous government. The opposition widened its majority in April 2024, and the CRS describes the months that followed as escalating gridlock: a third presidential veto of a bill calling for a special prosecutor, a budget cut in committee, impeachment motions against prosecutors and the state auditor.

The martial law declaration of 3 December 2024 came out of that deadlock, and Yoon described the opposition as "anti-state forces". After the assembly impeached him on 14 December the pattern continued one level down: the acting president, the prime minister, was himself impeached on 27 December by 192 votes to 0 after declining to appoint three Constitutional Court justices, and the finance minister became acting president in turn.

How the Constitutional Court checks both branches

The Constitutional Court has nine justices, each serving six renewable years and barred from party politics. All nine are appointed by the president, but three must come from those selected by the National Assembly and three from those nominated by the Chief Justice of the Supreme Court. It rules on the constitutionality of laws, on impeachments, on the dissolution of parties, on disputes between state bodies and on constitutional petitions, and any decision against a law, a president or a party needs six votes.

Its impeachment record is the clearest measure of what it does. On 14 May 2004 it overturned the assembly's impeachment of Roh Moo-hyun and reinstated him. On 10 March 2017 it upheld the impeachment of Park Geun-hye. On 4 April 2025 it upheld the impeachment of Yoon Suk Yeol unanimously, eight to none, with the bench still one short of its full nine. Its rulings reach well beyond presidents: on 28 June 2018 it found the Military Service Act unconstitutional for making no civilian alternative for conscientious objectors, and the Supreme Court recognised objection as grounds for refusing service that November.

The ordinary courts sit under a separate Supreme Court, whose justices are appointed by the president with the assembly's consent. Freedom House, in its 2025 report, lowered its score on whether elected officials determine policy from 4 to 3 because of the martial law declaration, and recorded that the lifting of martial law had restored the press and assembly freedoms it suspended.

How the parties split and merge

Two broad camps have organised politics since democratisation: a liberal camp now carried chiefly by the Democratic Party of Korea and a conservative camp carried by the People Power Party, formerly the United Future Party. The names change more often than the camps. The Politics of South Korea article describes a history of splits and mergers, parties built around leaders with regional bases, and a system labelled a "partyless democracy", in which the patronage of faction leaders shapes who is nominated.

Regional loyalty is part of it, and the article traces it back as far as the Silla-Baekje rivalry. Under Park Chung Hee the government favoured his native Gyeongsang province and neglected Jeolla, where Kim Dae-jung built his political base, according to the Gwangju Uprising article. A newer strand is what researchers call fandom politics: organised supporters of one politician, dating from a group formed around Roh Moo-hyun in May 2000 and matched by a conservative counterpart from 2004.

Election law is unusually strict. Campaigning door to door is banned, and Freedom House notes that legal bans on pro-North Korean activity limit some legitimate political expression. It also records regular rotations of power: the presidency has changed hands between the two camps at the elections of 1997, 2007, 2017, 2022 and 2025.

Where Freedom House finds the record falls short

Freedom House's report on 2024 describes civil liberties as generally respected and names the exceptions. Legal bans on pro-North Korean activity, under the National Security Law, affect legitimate expression, and during 2024 the authorities raided people and groups suspected of illegal support for the North. Journalists were indicted that year for allegedly defaming the president. The report calls corruption a persistent threat, with scandals implicating successive governments and company executives, and politicians of both camps were under investigation or on trial during the year.

Its sharpest criticism concerns women. The report describes misogyny as a chronic problem and records domestic violence, gender-based violence and deepfake pornography as common despite the laws against them. In September 2024 the assembly made possessing or viewing sexually explicit deepfakes a crime punishable by fines or up to three years in prison, and stalking charges rose after 2023 amendments let prosecutors proceed without the victim's approval.

Religion reaches into law-making in a less visible way. The Politics of South Korea article describes both large parties as wary of organised Protestant voters in closely fought constituencies around Seoul and Gyeonggi, where a seat can turn on 1 to 3% of the vote, and ties that caution to the absence of a comprehensive anti-discrimination law. A 2025 opinion poll found voters' main concerns were jobs, institutional reform, housing and polarisation.

How the country is divided for local government

Local government is semi-autonomous, with its own elected executives and councils, and local elections have been held since 1995. There are seventeen first-level divisions.

The capital, Seoul, is the one special city. Busan, Daegu, Incheon, Gwangju, Daejeon and Ulsan are metropolitan cities, outside any province. The provinces are Gyeonggi, Gangwon, North and South Chungcheong, North and South Jeolla, North and South Gyeongsang, and Jeju, which is a special self-governing province. Sejong is a special self-governing city.

The constitution claims more than this. Article 3 defines the territory as the whole peninsula and its islands, and the Wikipedia country article notes provinces that belong to the territory under the constitution "but have not been recovered". North Korea, for its part, abandoned peaceful reunification as a goal in 2024 and labelled the South its most hostile state.

Who South Korea stands with

The alliance with the United States is the fixed point. It began with the American administration of the South from 1945 and the war of 1950, and after the armistice the two states signed a Mutual Defense Treaty under which an attack on either in the Pacific area calls for a response from both. A substantial US force, mainly ground and air units, is stationed in the country. In wartime a combined command still places South Korean forces under an American-led structure, and the handover to South Korean command has been scheduled and postponed repeatedly. South Korean men are required to serve in the military, typically for 18 months.

South Korea joined the United Nations in 1991, at the same time as North Korea. It joined APEC in 1989, the WTO on 1 January 1995 and the OECD in 1996, and it sits in the G20 and in RCEP. Relations with China have improved steadily since 1992. China took $130.8 billion of South Korean exports in 2025 and the United States $122.9 billion, according to the trade ministry.

Japan is the harder relationship. Disputes over the colonial period and wartime conduct, over the Liancourt Rocks and over Japanese politicians' visits to the Yasukuni Shrine recur, although ties improved in the 2020s and a trilateral summit with the United States at Camp David in 2023 committed the three to coordinate on democracy and human rights.